PET Separator Base Material Preventing Coating Wrinkling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithium ion secondary battery separators made from polyolefin resins are prone to melting and shrinking during abnormal heat generation, leading to short circuits, and existing non-woven fabric base materials face issues with wrinkling, productivity, and achieving both low internal resistance and high tensile strength.
Innovation Solution
A non-woven fabric base material comprising crystalline polyethylene terephthalate fibers and polyethylene terephthalate binder fibers with specific fiber length and diameter ranges, and incorporating 3,5-dicarbomethoxy benzene sulfonic acid as a copolymer component, treated with processes such as coating, electrospinning, or solid electrolyte coating to enhance strength and prevent wrinkling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a non-woven fabric base material with small thickness is used to produce thin separators, then the separator thickness is reduced, but the base material becomes easy to wrinkle during coating, which declines productivity
Solution Approach 1:
The patent applies parameter changes by precisely controlling the fiber diameter (0.1-10 μm) and fiber length (2 mm or less) of the non-woven fabric base material. By optimizing these physical parameters, the base material achieves sufficient mechanical strength and dimensional stability to prevent wrinkling during coating operations, while maintaining the desired thin thickness for high-performance separators
Solution Approach 2:
The patent uses composite materials by combining crystallized PET fibers with amorphous PET binder fibers in a specific composition. The crystallized fibers provide structural integrity and heat resistance, while the amorphous binder fibers ensure proper adhesion and flexibility. This composite structure enables thin separators to maintain stability during coating without wrinkling, thus preserving productivity
2Strength
If the melting of PET binder fiber is advanced to enhance the strength of the non-woven fabric base material, then the tensile strength is improved, but the PET binder fiber fills up pores inside the base material, which worsens electrolyte retention and increases resistance
Solution Approach 1:
The patent applies local quality by creating spatial differentiation in the base material structure. The crystallized PET fibers are distributed to provide localized strength enhancement at critical points, while the amorphous PET binder fibers are positioned to maintain pore connectivity in other regions. This localized quality distribution allows the material to achieve high tensile strength without compromising electrolyte retention pathways
Solution Approach 2:
The patent utilizes porous materials by carefully controlling the porosity and pore size distribution of the non-woven fabric base material. The structure maintains adequate pore volume and connectivity to ensure proper electrolyte retention and ionic conductivity, while the strategic placement and melting characteristics of binder fibers provide necessary mechanical strength without excessive pore filling
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution prevents wrinkling during coating, improves productivity, and achieves both low internal resistance and high tensile strength, ensuring effective electrolyte retention and reduced resistance in lithium ion secondary battery separators.
Implementation Method 1
when the melting of a PET binder fiber is advanced to enhance the strength of the non-woven fabric base material
Implementation Method 2
the non-woven fabric base material comprises a crystalline polyethylene terephthalate fiber and a polyethylene terephthalate binder fiber
Implementation Method 3
a treatment in which a coating liquid containing an inorganic pigment is coated
Implementation Method 4
a treatment in which a fine fiber layer is formed by an electrospinning method
Data Source
AI summary
A non-woven fabric base material for a lithium ion secondary battery separator composed mainly of a polyethylene terephthalate fiber, characterized in that the non-woven fabric base material comprises a polyethylene terephthalate binder fiber containing 3,5-dicarbomethoxy benzene sulphonic acid as a copolymer component..